This invention relates generally to computer accessories, and more particularly to accessories adapted for use with digital personal assistant devices.
In the prior art, digital still cameras have been adapted to work with workstations, personal computers, and even lap-top devices.
In U.S. Pat. No. 5,708,853, Sanemitsu describes a Personal Computer Memory Card International Association (PCMCIA) card that includes an image input device. The card can be inserted into an PCMCIA slot of a lap-top computer. In one configuration, holes are formed in the casing of the lap-top so that an image input device can acquire a picture. The card requires that the computer device is equipped with PCMCIA xe2x80x9cslotxe2x80x9d and mounting frame.
There are a number of problems with this configuration. First, the PCMCIA standard requires that the dimensions of the slot be about 9xc3x976xc3x971.5 cm. For many modern PDA""s, such as a PalmPilot (12xc3x978xc3x971.5), the slot and frame would consume nearly the entire interior of the PDA. In such applications, the card according to Sanemitsu would be totally unworkable. More recent PDA are even smaller than the PCMCIA card.
Second, the PCMIA card has two connectors, front and back. The back 64 pins interface to the computer, and the front pins, which vary depending on the communications interface, need to be connected to some type of transmission controller connected to a communications line. Sanemitsu suggests an ISDN telephone line. This is a severe limitation making the device totally useless in most PDA type of environments where a communications line is not always available. In combination, the size of the PCMIA card and the requirement for connection to a communication line make this solution completely impractical for modem mobile personal digital assistants.
In U.S. Pat. No. 5,948,086 Lin describes an electronic still camera that is adapted for use with a portable computer that is equipped with a housing for receiving a removable and rechargeable battery pack. This arrangement also has a number of problems similar to Sanemitsu""s camera. First, the size of a rechargeable battery pack overwhelms any modern PDA. Second, this camera presumes that the device is equipped with a removable battery. This is not the case with most PDAs, which are powered by disposable batteries.
In other configurations, the camera is loosely tethered to the PDA. This presents an ergonomic problem since it is awkward to handle both the PDA and camera at the same time.
Therefore, it is desired to provide a camera system for a PDA that is entirely mounted outside the PDA device in a rigid and ergonomic manner.
As a second characteristic, prior art cameras only acquire still or moving images. Other than controlling exposure, there is very little control of how the images are acquired. Therefore, there is a need for a camera that can be used with a PDA so that the PDA can control higher level camera functions, such as image enhancement, x-y projections, resolution, and the like.
There is even a greater need for an adaptable camera system that can also perform computer vision applications. Over the years, a number of computer vision applications have been recognized as useful tools. Such applications include object recognition, content based image retrieval, visual navigation, robotics, surveillance, human-computer interface, virtual reality, 3D shape recovery, and medical and industrial vision problem. In the prior and, computer vision applications typically consume the bulk of a workstation computing resource. It is unlikely that any known PDA is configured to perform computer vision applications on images acquired by an attached camera. Therefore, it is desired to provide a PDA with computer vision capabilities as an accessory.
An accessory is adapted to operate with a personal digital assistant. The accessory includes a housing and an electrical interface externally accessible by the personal digital assistant. A pair of opposing members are arranged on the housing to mount the personal digital assistant in a fixed relationship with the accessory. The opposing members are spring loaded by a spine portion of the housing.
In one aspect of the invention, the accessory is a computer vision system adapted to operate with a personal digital assistant. The system includes an image sensor for acquiring images. An sensor microprocessor is coupled to the sensor. A vision microprocessor is coupled to the sensor microprocessor and an instruction memory and a data memory. A communication interface is coupled to the vision microprocessor, and for interfacing with the digital personal assistant.